1. The act of breaking out or bursting forth; as: (a) A violent throwing out of flames, lava, etc., as from a volcano of a fissure in the earth's crust. (b) A sudden and overwhelming hostile movement of armed men from one country to another. Milton. (c) A violent commotion. All Paris was quiet . . . to gather fresh strength for the next day's eruption. W. Irving.

2. That which bursts forth.

3. A violent exclamation; ejaculation. He would . . . break out into bitter and passionate eruditions. Sir H. Wotton.

4. (Med.)

Defn: The breaking out of pimples, or an efflorescence, as in measles, scarlatina, etc.

ERUPTIONAL
E*rup"tion*al, a.

Defn: Eruptive. [R.] R. A. Proctor.

ERUPTIVE
E*rup"tive, a. Etym: [Cf. F. éruptif.]

1. Breaking out or bursting forth. The sudden glance Appears far south eruptive through the cloud. Thomson.

2. (Med.)